The present invention relates to a system and method for prevention and treatment of peri-implant infection.
Dental implants have become the new standard of care for replacement of missing teeth. As shown in FIG. 1, the dental implants consist of a titanium fixture 1 that may either be threaded or unthreaded on the exterior and usually has a sintered surface. The fixture 1 is placed into the jaw bone surgically by drilling a hole in the bone and screwing or tapping the fixture in, or it is simply screwed into a fresh tooth extraction site. This fixture 1 is then used to retain prosthetic teeth or dentures. Typical dental implant fixture dimensions are 5 mm×10 mm but considerable variation exists. Over time, the supraosseous implant surface can become colonized with a bacterial biofilm that inflames the gum tissue and often destroys the supporting bone that retains the implant which can result in the loss of the implant. Few viable treatment options exist for this problem. This bacterial mediated inflammatory process likely increases the risk for other systemic diseases such as cancer, cardiovascular disease and stroke, as has been shown in periodontitis patients.
As shown in FIG. 2, the implant site is prepared by surgically reflecting the gum 2 which exposes the jawbone 3, then drilling a hole 4 into the bone 3. The implant fixture 1 is then threaded or gently tapped into the prepared hole 4. The goal is to have the implant fixture 1 positioned such that the final biting load will be perpendicular to the jaw and that the coronal extent of the implant 1 is placed at the crest of the bone or in close proximity thereof (i.e. the entire implant fixture 1 is embedded in bone 3). The gum 2 is then sutured to close the surgical site at which point the bone grows into the implant surface undisturbed which is called “osseointegration” and usually takes about 3-6 months. Variations to this technique include: 1) implants that are self-tapping, 2) implants that are placed immediately after extraction into a fresh extraction site with a tooth replacement installed on the implant at the same visit, and 3) drilling the hole in bone directly through the gingiva without reflecting the gingiva.
After osseointegration has been attained, which is simply assumed after 3-6 months based on various research studies, the implant is surgically uncovered, unless it has been placed directly through the gingiva or in an extraction site. As shown in FIG. 3, an abutment 5 is screwed onto the exposed coronal end of the fixture 1. This abutment 5 extends from the height of the bone 3 coronally through the gingiva. The final restoration is usually a crown 6 which is either: 1) cemented or screwed onto the abutment 5 or, 2) is an integral part of the abutment 5 that is screwed onto the fixture 1. Note that there exists a portion of this implant system that is supraosseous yet subgingival, and is in contact with the gingiva. This “Transgingival Portion” (hereinafter “TGP”) usually has a smooth surface to not promote bacteria or debris retention. Variations of an implant borne restoration include many implants placed into the jaw that are: 1) connected with a bar that is used to support a removable denture; 2) supporting a removable denture without a bar; and 3) connected with a bridge of crowns.
Implants can fail or become diseased for several reasons, e.g., due to microorganism colonization of the implant surfaces adjacent to the gingiva and bone, as well as iatrogenic distortion/destruction of the fixture's internal abutment attachment mechanism due to issues such as cross-threading or breakage of the abutment attachment screw.
Peri-implantitis and Peri-implant Mucositis:
As in natural teeth, the supragingival portion of the implant (which usually consists of only the restoration) will colonize with gram-positive aerobic bacteria. If this is not removed by the patient with proper oral hygiene on a daily basis, the gum tissue adjacent to the bacterial growth becomes reversibly inflamed which is known as Peri-implant Mucositis. This promotes the colonization of the subgingival implant surface with a gram-negative anaerobic bacterial biofilm. These bacteria can destroy the bone supporting the implant which is known as Peri-implantitis. Peri-implantitis prevalence rates approach 50%, depending on criteria, with 5% of all implants being lost to this disease over a 10-year period of time. The inflammation found in both of the above states is associated with increased risk of systemic diseases such as cardiovascular disease, cerebrovascular disease, and cancer.
Peri-implantitis Pathogenesis:
The pathogenesis of peri-implantitis appears to be virtually identical to periodontitis with only slight variations. As the bone around the implant is destroyed, the sintered and threaded implant surface becomes exposed to the gingival pocket and the bacteria found there. This extremely irregular implant surface is the ideal environment for the growth of the bacterial biofilms that cause peri-implantitis as it is highly bacteria retentive. It is also very difficult to arrest peri-implantitis due to the inability to access and disinfect this rough implant surface. Surgical success rates in treating peri-implantitis approach 60%, while nonsurgical treatment has been shown to be virtually ineffective. These low success rates are most likely due to: 1) the exogenous biofilm matrix which protects the bacteria, 2) the fact that the implant surface is such an ideal place for these biofilms to grow, 3) the difficulty of accessing and disinfecting these subgingival surfaces with either surgical or nonsurgical treatment, and 4) the patient's inability or difficulty in maintaining the supragingival surfaces free of bacteria.
Nonsurgical Treatment:
A nonsurgical technique to disinfect implants, as developed by Applicant, involves inspecting and debriding the subgingival portion of the implant with a periodontal endoscope while irrigating with various anti-infective chemical agents. While this technique has demonstrated an undocumented 80-90% success rate by eliminating inflammation, it is very costly and time consuming. In addition, it is not a cure. Therefore, if the patient's daily oral hygiene is inadequate (due to improper technique or access problems) then the transgingival implant surfaces will recolonize with periodontal pathogens causing recurrence of either peri-implant mucositis or peri-implantitis necessitating retreatment.
Destruction of the Implant-Abutment Connection:
The vast majority of currently placed implants possess a threaded screw hole in the coronal end that provides a means of attachment of the abutment and/or the restoration. With wear and tear, mechanical failure or operator error, these threads can become damaged which may render the implant completely unusable.